1. The Field of the Invention
The present invention relates to a control system for memory storage device having two different interfaces, and more particularly relates to an application of IC of the control system which provides an IDE interface and an USB interface that are capable of cooperating to function at the same time.
2. Description of the Related Art
The flash memory is designed to provide features such as erasable, programmable and non-volatile, thus it provides a suitable medium for a general portable memory storage device. The general portable memory storage device (memory chip) available in the market includes Secure Digital, Multi Media Card, Memory Stick, Compact Flash, Smart Media and so on. There is no unified interface for communicating with a server for these storage devices, and therefore a control system of the memory storage device is demanded for communicating with the server. The so-called control system for memory storage device is, for example, flash memory card reader that is capable of communicating with a server (such as computer) for receiving the command from the server to manage, erase, save and retrieve the data from the memory card.
The transmission interface available for memory storage device is generally classified into two major types, namely parallel type and serial type. The parallel type, such as Parallel Port, IDE, PCMCIA and alike, have the advantage of high transmission speed, however, the transmission wires required for this type is plenty so the cost is correspondingly higher; and the serial type, such as Serial Port, USB, IEEE1394 and alike, have lower transmission speed. The most commonly used transmission interface is IDE because IDE has high transmission speed, easy to install, advanced technology and so on. Generally IDE is used in vast storage device, for example, for data saving and retrieving traffic between the server and hard disc driver, or between the server and the CD ROM. Furthermore, USB is currently a popular serial transmission interface, and the advantage provided by USB is due to its capability to receive a plurality of USB devices and supply HOT SWAP and PLUG & PLAY features, and because of such popular features, USB is generally used as computer peripheral product.
Additionally, the HOT SWAP and PLUG & PLAY features makes USB interface as a first choice transmission interface for electronic devices such as application IC of the control system for memory storage device, such as memory card reader. There are several portable information products available in the market that use IDE interface, such as DVD player, and the specification is different compared to USB interface, and therefore there is a barrier in designing that needs a break-through, for instance, the palm DVD uses IDE as transmission interface for memory storage device, for having the function of memory card reading. Accordingly, an interface converting mechanism is required for converting USB interface into IDE interface.
Referring to FIG. 1, illustrates a conventional data transmission process, the common method of converting USB interface into the IDE interface is to install a USB/IDE interface converting circuit 11 within the control system 10 of a memory storage device such as memory card reader to enable the control system 10 of the memory storage device to transmit data through a memory interface 13 to the application IC 14. When the memory chip is installed into the memory chip slot 12 of the control system 10 of the memory storage device, and after processing by the application IC 14, the data is transmitted to an USB/IDE interface converting circuit 11 through the USB interface 15. Furthermore, the data format is converted into IDE interface from USB interface by the USB/IDE interface converting circuit 11 then transmitted to the server, and then the data is stored in the IDE formation and finally transmitted to a portable information product 16. Such a processing procedure for the product design is inefficient and expensive, such procedures bound to suffer from the defects and high power consumption.